Nonenzymatic Glucose Sensing Employing a Patterned Substrate Miniaturized Device-on-Mask

Miniaturized analytical instruments have drawn significant interest as point-of-care testing requirements have grown. Due to their facile operation, portability, high sensitivity, and quick analysis times, miniature electrochemical sensors have been much sought after in analytical research. In this letter, we have developed a low-cost three-electrode system on a miniaturized patterned substrate as a device-on-mask capable of nonenzymatically detecting blood equivalent glucose. The design inculcates a built-in reservoir to direct samples to the three electrodes, contain large sample volumes, prevent spillage, and avoid short circuits from occurring. Response of the sensor over a wide range of blood equivalent glucose concentrations (50–350 mg/dL) is highly linear (R
²
∼0.98). The active sensing material, poly(3,4-ethylenedioxythiophene) polystyrene sulfonate modified with reduced graphene oxide, is capable of detecting glucose with a sensitivity of 139.25 μAmM
⁻¹
cm
⁻²
and 22.357 μΩ
⁻¹
mM
⁻¹
; a detection limit of 6.97 and 0.098 mg/dL using cyclic voltammetry and electrical impedance spectroscopy, respectively, which were the techniques utilized to characterize the device and showcase its remarkable sensing capability.